Batten control for sailboats

ABSTRACT

A positive batten inversion system for control of the battens used to stiffen the leech of a sail for a sailboat comprises a pair of control lines for each batten that extends beyond the backstay run up from the tack, along either side of the luff of the sail, to blocks secured to the sail near the luff and slightly below an imaginary line connecting the batten centerline to the luff. From the blocks, the lines run out to the leech and are secured to the leech just above the after end of the battens. Accordingly, the lines cross the battens at a very acute angle. Tensioning the lines causes the batten to be inverted and/or compressed, allowing it and the leech of the sail to pass by the backstay.

FIELD OF THE INVENTION

This invention relates to control of the battens used to stiffen theLeech portions of the fore-and-aft sails of a sailboat. Morespecifically, it would be useful to provide positive control offull-length battens in particular, rather than relying on their changingtheir camber during manuevers. In particular, it would be desirable toprovide a positive control for urging the battens of a mainsail past thebackstay during manuevers.

BACKGROUND OF THE INVENTION

The sailboats with respect to which this invention is relevant aretypically rigged to fly at least one generally triangular fore-and-aftsail, e.g., a “mainsail”. Although the invention is described hereinprimarily in that connection, it is not limited thereto; the inventionmay also have use in connection with battened forseails or “jibs”, andwith other fore-and-aft sails in boats of other types, e.g., mizzensails on boats with multiple masts.

Refering now to the case of the mainsail, the forward side or “luff” ofthe mainsail is supported by a mast; the lower edge of the mainsail, or“foot”, is secured to a boom pivoted to the mast; and the rearward edgeof the sail, or “leech”, flies freely. The uppermost corner of the sail,where the luff and leech meet, is called the “head”; the lower forwardcorner, where the foot and luff meet, is called the “tack”, and theafter lower corner, where the leech and foot meet, is termed the “clew”.

To stiffen the leech, so that it retains its desired aerodynamic shapeunder a wide range of conditions, a number, usually four to six, of“battens”, comprising resilient strips of a lightweight planar materialof carefully chosen flexibility, are commonly inserted into pocketsextending forward from the leech, usually parallel to the foot orperpendicular to the leech. It is increasingly popular for at least theuppermost batten to be full-length, that is, to extend from the leech tothe luff.

All else being equal, a sail of larger area will be more powerful than asmaller sail, so there is a constant trend to increase sail area. Onelimitation imposed on the size of the mainsail that can be carried isthe presence (in nearly all cases) of a “backstay”, a tension memberrunning from the top of the mast toward The stern of the boat, part of aset of such members (the “standing rigging”) that support the mast.Traditionally, the leech of the sail, particularly near the head, hasbeen designed so that it almost completely fills the area between themast and backstay, in order to maximize sail area while preventing theleech from interfering with the backstay as the sail passes over thecenterline of the boat during “tacking” and “jibing” manuevers.

More recently, mainsails are increasingly being cut so that theirleeches extend beyond the backstay. Where the leech is aft of animaginary line connecting head and clew, it is said to have “roach”, sothe trend is to more and more roach. A problem with doing so is that theupper battens in particular tend to interfere with the backstay duringtacking and jibing manuevers, during which, as noted above, the sailcrosses the centerline of the boat; as the leech of the sail slides pastthe backstay, the stiff battens tend to catch on the backstay,preventing the sail from coming completely through the manuever andcausing various difficulties. This is particularly a problem withfull-length upper battens, where the inner end of the batten bears moreor less directly against the mast. To the extent this problem has notbeen solved it prevents adding roach, as desired.

One solution to this problem that has been tried with some degree ofsuccess is to attach one end of a “whip”, a flat springy strip ofmaterial, not unlike a sail batten, to the masthead, and the other endto the backstay, in such a way that the whip tends to urge the backstayaway from the masthead. Then, during manuevers, tension on the backstayis substantially eased, so that the whip can pull it out of the way ofthe leech of the sail as the boat tacks or jibes; after the manuever,the backstay must then be retensioned. This approach has many drawbacks:it adds weight and windage at the masthead, which is very undesirable,it adds significantly to the duties required of the crew, and if thewhip breaks or fails it may be impossible to tack or jibe the boatwithout at least partially lowering the sail, which is very awkward andtime-consuming, and may even be dangerous.

Thus, a need exists in the art for a device or system that will allowsails to be built with leeches extending substantially aft of thebackstay, employing full-length battens as desired, and which willpermit the battens to be urged past the backstay during tacks and jibes.Additional constraints to be met are that this system or device not addexcessive weight, cost, or complexity, either as to use while sailing orwhen removing and stowing the sails, and that it be reliable and easy toinstall and use.

SUMMARY OF THE INVENTION

The present invention satisfies the above needs of the art, and complieswith the listed constraints, by its provision of a positive batteninversion system. A pair of control lines for each batten that extendsbeyond the backstay run up from the tack, along either side of the luffof the sail, to pulleys or “blocks” secured to the sail near the luffand slightly below an imaginary line connecting the batten centerline tothe luff. From the blocks, the lines run out to the leech and aresecured to the leech just above the after end of the battens.Accordingly, the lines cross the battens at a very acute angle.

The system of the invention can be used in several different ways. Inone possible practice, the tack or jibe manuever is completed as usual;if the batten hangs up on the backstay, the control line on theappropriate side of the sail, the free end of which hangs near the tack,is pulled downwardly, causing the batten to be collapsed somewhat,allowing the leech to slide past the backstay. As soon as the battenpasses the backstay the control line can be released.

In another method of practice of the invention, the control lines arepulled prior to the tack or jibe. This causes the battens first to be“inverted”, that is, reverse their direction of curvature, and then becompressed, allowing the leech to pass by the backstay. Morespecifically, while the boat is sailing on a first tack, the sail iscambered to leeward, i.e., forms an aerodynamically curved shape; thebatten's characteristics are chosen specifically to assist in formingthe proper sail shape. Absent the invention, when a tack or jibe isinitiated, so that the leech of the sail must brush past the backstay,the tip of the cambered batten, being bent toward the backstay, tends tocatch on the backstay. The control lines provided according to theinvention are operated to cause the batten to invert, taking a camber ofthe opposite sense, at or prior to the time the batten and leech pass bythe backstay.

Finally, the control lines provided according to the invention can beused as additional sail-shaping tools, both to preclude unwanted batteninversion (as sometimes happens in light air conditions) or to provide adesired amount of curvature to the sail.

The control lines can be confined near the luff of the sail in pocketsor sleeves of sailcloth sewn to the sail, or otherwise, e.g., through aseries of rings or the like. The lines and blocks can be very light,since the applicable loads are very small, and do not interfere withmovement of the sail, or its removal from the mast and stowage.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood if reference is made to theaccompanying drawings, in which:

FIG. 1 shows a mast, boom, backstay, and mainsail, as seen from theright or “starboard” side of a sailboat;

FIG. 2 shows the upper portion of the sail and mast, from the starboardside, while the boat is on “port tack”, i.e., with the wind coming overthe left or “port” side;

FIG. 3 shows a similar view, showing the battens becoming inverted astension is applied to the control lines;

FIG. 4 shows a similar view, showing the battens having been inverted asfurther tension is applied to the control lines;

FIG. 5 shows a similar view, showing the battens, having been inverted,becoming compressed as further tension is applied to the control lines,so that the battens and leech can pass by the backstay;

FIG. 6 shows a similar view, showing the battens having become extendedon the starboard tack, as tension is released from the control lines;and

FIG. 7 illustrates a several alternative implementations of theinvention, with the sail on port tack, as in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows, as mentioned, the mast 10 and associated components of asailboat from the starboard side. A mainsail 12 is secured along itsluff 14 to the after side of mast 10. The head 16 of sail 12 is hoistedto the top of mast 10 by a halyard (not shown), and its foot 18 iscontrolled by a boom 20 pivoted to the mast 10 at or near the tack 22 ofsail 12.

As noted, in the usual case the mast 10 is supported by a number oftension members, or standing rigging, including the backstay 24, whichcommonly runs from a masthead crane 26 at the top of mast 10 to besecured to the boat's deck, as indicated at 28. If, as is currentlypopular, and as shown, the leech 32 of the mainsail extends past thebackstay 24, i.e., the sail has roach, the leech 32 will brush againstthe backstay 24 during tacking and jibing manuevers and may be impededfrom passing by the backstay freely. This prevents the sail from beingcontrolled readily, as is highly desirable, and in some cases could bedangerous.

It is usual for a number of battens 30, usually strips of a stiff planarmaterial, to be disposed in pockets sewn or otherwise affixed to thesail and running forwardly from the leech, to support the sailcloth andensure that the leech retains the desired aerodynamic shape. One or moreof the battens may be “full-length”, i.e., run from the leech to theluff, so as to stiffen the entire “chord” of the sail in this region, asshown by uppermost batten 30 a in FIG. 1.

It will be apparent that the presence of the battens exacerbates theproblem of pulling a sail with substantial roach past the backstayduring manuevers, especially where one or more full-length battens areused, since the stiffness provided by the battens resists the collapsingof the sail that is required in order that it can pass by the backstay.

According to the present invention, at least one control line 40 isadded to either side of the sail. Only the line(s) on the starboard sideof the sail are shown in the drawings hereof; similar lines would beinstalled similarly on the port side of the sail.

Thus, according to the invention, a first control line 40 runs from alower end disposed near the tack 22 of the sail, upwardly near the luff14 to a block 42 secured to the sail, and thence to the leech 32, wherethe upper end of control line 40 is secured. It will be appreciated thatexerting tension on the lower end of control line 40, that is, pullingdownwardly, will urge the leech 32 toward the mast. In some cases, thuspulling the leech inwardly may itself be sufficient to pull the outerend of the batten 30 past the backstay 24, freeing the sail to tack orjibe, as may be. However, this may not always suffice, especially wherethere is a full-length batten, as at 30 a, extending between leech 32and luff 14; the stiff batten secured to the sail may preclude collapseof the sail by tension applied at an arbitrary point on the leech 32.

Therefore, according to another important aspect of the invention, theblock 42 is secured to the sail near the luff on one side (below, in theembodiment shown) of an imaginary line running along the centerline ofthe batten 30 a, while the upper end of the control line 40 is securedto the leech 32 on the opposite side of that line (thus, in theembodiment shown, above the centerline of the batten). Accordingly, thecontrol line crosses the batten 30 a at a rather acute angle A, whichmight be between 5-30 degrees.

The effect of disposing the control line 40 so that it thus crosses thebatten, rather than running directly along the batten, is that thecontrol line contacts the batten (that is, contacts the surface of thebatten pocket in which the batten is disposed, in the usualconstruction) at or near the point of maximum curvature of the batten.Accordingly, and as will be more clear from discussion of FIGS. 2-6below, tension on the control line 40 tends to “invert” the batten, thatis, causes the batten to switch from being cambered in one sense, thatis, curved toward one side of the sail, to being cambered in theopposite sense. Having the control line cross the batten at an anglealso imparts a twisting force to the batten, further easing in itsinversion. Experiments performed by the inventor indicate that thushaving the control line cross the batten at an angle provides improvedresults as compared to a system in which the control line 40 weredisposed so that it was parallel to the batten.

As indicated, if more than one batten extends past the backstay, second(and additional) control lines 40′ can be provided, with a second block42′ located in the corresponding position with respect to the lowerbatten(s) 30. Control line 40′ can be spliced to control line 40, sothat a tug on a single line will cause both battens to be inverted. Asnoted, this procedure is very simple and can be accomplished by acrewmember as a matter of course each time the boat is tacked or jibed,simply by pulling downwardly on the appropriate control line.

As illustrated, the control line(s) 40, 40′ can be confined neatly nearthe luff 14 of the sail 12 by enclosure in elongated sleeves 44 formedby sewing strips of sailcloth to the sail near the luff. Alternatively,the control lines could be led to the vicinity of the tack by a seriesof rings or the like secured to the sail.

Further, again as noted above, a similar arrangement of one or morecontrol line(s), block(s), and sleeve is provided on either side of thesail, so that the battens can be inverted in either sense.

FIGS. 2-6 show stages in the inversion of the uppermost two battens of asail during a tack, from “port tack” (in which the wind is coming overthe left or port side of the boat) to “starboard tack”. These Figs. allshow the sail from the starboard side, essentially as if lookng upwardlyat the masthead. Thus, in FIG. 2, the sail is shown as during port tack,in that the sail 12 is curved to “leeward”, that is, away from the wind,toward the viewer. The battens 30, both of which are full-length in thisexample, are similarly cambered to leeward, toward the viewer. Thebackstay 24 is behind the sail, so that if the boat is tacked, forcingthe sail to pass by the backstay, the potential exists for the leech 32,especially as stiffened by the full-length cambered battens 30, to hangup on the backstay 24. FIG. 2 also shows reinforcing patches 46,provided to prevent the load from the control line from distorting theshape of the leech.

In FIG. 3, tension T has begun to be exerted on the control lines 40,which forces battens 30 to begin to be inverted, by assuming an“S”-shape, as illustrated. As illustrated, the lines contact the battens(which will typically be confined in pockets of sailcloth, not shown) ator near the point of maximum depth of curvature. Accordingly, applyingtension on the control lines causes a transverse force to be exerteddirectly to the battens at or near the point which is most effective incausing the battens to take the “S-shape” shown, and then immediately toinvert, taking the opposite camber.

In FIG. 4, the battens have been inverted, that is, have “popped” intothe opposite camber, although the boat has not yet tacked (as indicatedby the fact that the backstay 24 is still behind the sail). In FIG. 5,further tension T is applied (the application of tension beingessentially a continuous process), causing the inverted battens 30 tobecome compressed, so that the leech 32 of the sail passes under thebackstay 24. Now the boat can be tacked, so that the sail passes underthe backstay, and the tension eased in lines 40; the sail then takes thenormal starboard tack configuration in FIG. 6.

It will be appreciated that in practice of the invention according tothe foregoing description of the use of the invention, the control linesprovided according to the invention are tensioned to invert the battensbefore tacking, as this will lead to the smoothest operation. It isnonetheless within the invention to operate the control lines only aftertacking, and indeed to so only when the batten and leech in fact arehung up on the backstay; in many boats this does not occur on each tackor jibe. It is also within the invention to maintain tension on thecontrol lines 40 after tacking, to control the shape of the sail, or topreclude repetitive inversion of the battens (as can happens inparticular during light-air sailing, interfering with the aerodynamicshape of the sail); this can readily be accomplished by assembling smallcleats on either side of the sail near the tack 22, as indicated at 50in FIG. 1.

Finally, FIG. 7 shows several alternative constructions also within theinvention.

At 46 there is shown a partial-length batten, with the control line atan angle thereto as above; in this case, the batten would be inverted byoperation of the control line, as above. At 48 there is illustrated apartial length-batten with the control line 40 attached to its inboardend; in such case the control line serves primarily to pull the entireleech section of the sail under the backstay, rather than first invertand then compress the batten, as in the above.

It is also within the scope of the invention employ a similar controlline arrangement for inversion of battens on sails other than mainsails.For example, battens are sometimes used on foresails, or “jibs”; thesealso can become hung up on the standing rigging, or on the mast. Theinvention can readly be adapted to provide positive control of suchbattens on foresails.

Thus, while a preferred embodiment of the invention and severalalternatives have been shown in detail, the invention is not to belimited thereby, but only by the following claims.

1. A batten inversion control system for a sail of a sailboat, said sailcomprising one or more substantially resilient batten members affixed tothe sail and extending forward of the leech of the sail, said controlsystem comprising: at least one control line and at least one block oneither side of said sail, said control line being disposed so as toextend from a position near the tack of said sail upwardly along theluff of said sail to a point on the luff near the intersection of animaginary line extending along the centerline of the batten and theluff, said block being secured to the sail near said point, and saidline passing around said block and toward the leech of the sail, saidline being secured to the leech of the sail near the intersection ofsaid imaginary line with the leech of the sail.
 2. The control system ofclaim 1, wherein said block is secured to the sail on one side of theintersection of said imaginary line with the luff of the sail, and saidcontrol line is secured to the leech of the sail on the opposite side ofthe intersection of said imaginary line with the luff of the sail, suchthat said control line crosses the batten at an acute angle.
 3. Thecontrol system of claim 2, wherein said control line is located withrespect to said batten so as to pass over or near the point of maximumcurvature of said batten.
 4. The control system of claim 2, wherein saidblock is secured to the sail below the intersection of said imaginaryline with the luff of the sail, and said control line is secured to theleech of the sail above the intersection of said imaginary line with theluff of the sail.
 5. The control system of claim 2, wherein said acuteangle is between about 5 and about 30 degrees.
 6. The control system ofclaim 1, further comprising a cleat affixed on either side of the sail,for maintaining a desired tension in said control line.
 7. The controlsystem of claim 1, wherein said sail is sized such that at least one ofsaid battens and the leech of the sail tend to interfere with therigging of said sailboat during manuevers
 8. The control system of claim7, wherein said sail is a mainsail, and said battens tend to interferewith a backstay of the sailboat.
 9. The control system of claim 8,wherein if the sail comprises more than one batten extending past thebackstay, control lines and blocks are provided on either side of saidsail corresponding to said more than one battens extending past thebackstay.
 10. A sail comprising the control system of claim 1.